This invention relates to solid hair colorants and to application mixtures prepared therefrom for coloring hair.
1. Field of the Invention
The use of plant dyes in hair colorants has been known for some time. Fairly recent developments in this field are disclosed, for example, in FR 1 583 606, in BE 900219, in GB 2,190,104 and in DE 38 29 102. DE-A1 42 33 874 relates to hair tinting formulations in granular form which contain plant dyes in combination with synthetic substantive dyes.
2. Disussion of Related Art
Unfortunately, these known colorants based on plant dyes have the disadvantage that their ability to cover grey hair is very often unsatisfactory.
On the other hand, coloring with so-called oxidation dyes is known to the expert. In this case, coloring is achieved by the penetration of oxidation dye precursors into the hair where they react either together or with other oxidation dye precursors in the presence of an oxidizing agent to form the actual dyes. Excellent durable colors, which also cover grey satisfactorily, are obtained in this way. In view of the oxidizing agents used, however, unwanted impairment of the hair structure or even hair damage can occur, particularly in the event of fairly frequent application.
Accordingly, the problem addressed by the present invention was to provide hair colorants with which grey could be safely covered in the coloring of hair without any adverse effect on the hair structure.